Characteristics on Tempo-Spatial Distribution of Water Quality and Identification of Relevant Influential Factors in Small-Scale Basins of South China

Water environmental quality is key to river health, which may affect the virtuous cycle of the ecological environment in the basin as well as the sustainable development of the society and economy. Thus, to identify factors that may affect water quality from scientific perspective is fundamental to the solution of the water environment problem. Taking Binjiang Basin (a small-scale basin in South China) as an example and adopting the fuzzy comprehensive evaluation method and Spearman rank correlation analysis method, qualitative and quantitative analyses were made to define the tempo-spatial variation in water quality of the basin and to identify the major influential factors. The research findings showed that the overall water quality of Binjiang Basin was within its carrying capacity, except that in some parts of the basin (especially in the downstream areas) it had exceeded its carrying capacity and showed a tendency of deterioration; the water quality of the upstream areas was better than that of the downstream areas, while the water quality of the tributaries was superior to that of the main stream. For areas with intense human activities, the water quality was significantly inferior to that of the natural reach. From the distribution of water quality in the basin and the impact of human activities, urban domestic sewage, industrial wastewater and agricultural activities are the main factors affecting the water environment in the basin.